MDS PREP
What is the primary function of the epididymis in the male reproductive system?
1) Storage and maturation of sperm
2) Secretion of androgens
3) Formation of the spermatozoa
4) Fusion of gametes during fertilization
The primary function of the epididymis in the male reproductive system is the storage and maturation of sperm, allowing them to gain motility and the ability to fertilize an egg.
An increase of the pressure within one of the carotid sinuses would result in an increase in
1) Mean arterial pressure
2) Cardiac output
3) The activity of the pressor center
4) The activity of cardiac vagal fibers
Physiology
Answer: 4
An increase of the pressure within one of the carotid sinuses would result in an increase in The activity of cardiac vagal fibers
What is the primary effect of insulin on the skeletal muscles?
1) Stimulation of protein synthesis
2) Increased glycolysis
3) Increased glucose uptake and glycogen synthesis
4) Stimulation of muscle contraction
Answer: 3) Increased glucose uptake and glycogen synthesisExplanation: Insulin stimulates glucose uptake by muscle cells and promotes glycogen synthesis. It does so by increasing the number of glucose transporters on the muscle cell membrane and facilitating the transport of glucose into the cells.
The average time required for spermatogenesis in humans is:
1) 30 days
2) 42 days
3) 74 days
4) 120 days
Spermatogenesis, the process of producing mature sperm cells from spermatogonia, takes approximately 74 days in humans. This includes the development of spermatids and their subsequent transformation into spermatozoa.
What is the effect of vitamin E deficiency on cell membranes?
1) Increased fluidity
2) Decreased fluidity
3) No change in fluidity
4) Unknown
Vitamin E deficiency can lead to decreased fluidity of cell membranes, making them less flexible and more prone to damage.
What is the primary function of chymotrypsin in the digestive process?
1) Converting chymotrypsinogen into chymotrypsin
2) Breaking down proteins into peptides
3) Catalyzing the hydrolysis of disulfide bonds in proteins
4) Activating pepsinogen into pepsin
E) Releasing gastrin from gastric mucosa
Chymotrypsin is an endopeptidase enzyme that plays a crucial role in the digestive system by breaking down proteins into smaller peptides. It is activated from its precursor chymotrypsinogen by the enzyme trypsin. Once active, chymotrypsin hydrolyzes the peptide bonds at the carboxyl side of aromatic and bulky amino acids, such as phenylalanine, tryptophan, and tyrosine. This process is essential for the further digestion and absorption of dietary proteins.
What is the primary function of the enteric nervous system in the gastrointestinal tract?
1) Controlling digestive enzyme secretion
2) Regulating the absorption of nutrients
3) Coordinating muscular contractions and peristalsis
4) Secreting hormones that regulate digestion
E) Controlling blood flow to the GI tract
The enteric nervous system, also known as the gut-brain, is a network of neurons that controls the muscular activity of the gastrointestinal tract. It is capable of operating independently of the central nervous system but can be modulated by it. Its main function is to regulate motility and secretion within the GI tract, which includes coordinating peristaltic contractions that propel food and facilitate mixing and absorption.
What is the primary action of antidiuretic hormone (ADH) in the kidneys?
1) Increases the permeability of water in the proximal tubules
2) Increases the permeability of water in the collecting tubules and ducts
3) Stimulates glomerular filtration rate
4) Inhibits sodium reabsorption
Physiology
Answer: 2
ADH acts on the distal tubules and collecting ducts of the kidney to increase the permeability of the tubular epithelium to water. This results in the reabsorption of water and the concentration of urine, thereby reducing urine volume and increasing blood pressure.